A frequency re-use-1 scheme is commonly employed in OFDM based cellular networks. The frequency re-use-1 scheme involves each cell in a communication network using the same available bandwidth. Suppressing inter-cell interference to improve coverage and increase cell edge bit rates, however, is a challenge. A number of techniques have been considered to mitigate inter-cell interference.
One way is to use a fractional frequency re-use scheme, where each cell occupies only part of the available bandwidth. For example, a fractional frequency re-use approach for three base stations each associated with a respective cell involves each BS transmitting traffic to its respective cell using ⅓ of the available bandwidth. One drawback to such an approach is that it dramatically reduces network capacity, as compared to a frequency re-use-1 scheme where each cell uses all of the available bandwidth.
Another alternative is to use orthogonal frequency code division multiplexing (OFCDM), where frequency domain spreading is achieved using code division multiplexing. While such an approach achieves a spreading gain, performance degradation occurs as a result of orthogonality loss. In addition, when using such a scheme decoding and decoding hardware complexity increases.
Frequency hopping is another approach for inter-cell interference mitigation.
Yet another approach is to use macro diversity techniques including, for example, fast cell selection or soft handoff. Such an approach, however, introduces more complexity to the network.
Similarly, inter-cell interference cancellation techniques introduce more complexity in the receiver and are, therefore, not practical to be implemented everywhere.